The prior art closest to the compounds of the present invention is in Spanish patent No. 9201512 which describes a number of piperidine benzimidazole derivatives with antihistaminic and antiallergic activity of general formula ##STR2## The major structural difference between the compounds of the present invention and those of the said patent is the presence of oxygenated functions in the phenyl group substitution. An important pharmacophorous character has moreover been found for these oxygenated functions which consists essentially in a selectivity of action and provides a pharmacological profile distinct from that of other known antihistimaines. The compounds disclosed in this invention present an almost exclusive H.sub.1 antihistaminic pharmacological activity and are therefore devoid of action on other pharmacological receptors even at doses much higher than the therapeutic ones. Because of this selectivity in action, they are valuable instruments in treating allergic-type conditions, particularly allowing their unrestricted use by persons under any other concomitant medication whatsoever, and in the case of patients with pathological cardiocirculatory disturbances.